Field of the Invention
The present invention relates to a transport arm, a transport apparatus, and a transport method which hold and transport a substrate.
Background Art
For example, as a transport arm that holds and transports a substrate, Patent Literature 1 discloses a transport arm having a recess to avoid contact with the held substrate at a side of an arm main body where the substrate is supported. Specifically, in the arm main body of the transport arm disclosed in Patent Literature 1, a tip portion thereof includes an adsorption unit that holds a central portion of the substrate byway of vacuum adsorption. In addition, Patent Literature 2 discloses a transport mechanism that adsorbs and holds the substrate by using an adsorption hole formed on a lower surface side of a hand body. Further, Patent Literature 3 discloses a substrate transport apparatus where at least three holding units are arranged in parallel and at least two adsorption units are disposed in each holding unit so as to be position-adjustable along a longitudinal direction. Then, in general, the adsorption unit of the transport arm is formed of materials having stiffness such as aluminum, stainless steel and ceramics, or a material such as rubber.